# What is Asymmetry: Definition and 67 Discussions

Asymmetry is the absence of, or a violation of, symmetry (the property of an object being invariant to a transformation, such as reflection). Symmetry is an important property of both physical and abstract systems and it may be displayed in precise terms or in more aesthetic terms. The absence of or violation of symmetry that are either expected or desired can have important consequences for a system.

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1. ### A Uncertainty on an asymmetry signal

Hello! I have an experiment in which I measure the counts given some experimental parameters, call them ##E## in order to extract some physics parameter of interest, call it ##X##, so I have ##N(E,X)##. This ##N## (the number of counts) will have a statistical error (which goes like...
2. ### B Matter-antimatter asymmetry - a simple explanation?

Dear collegues, I would like to share and discuss a simple explanation to the matter-antimatter asymmetry. Maybe this explanation is too simple, but your feedback is appreciated. I would like to start with what inspired me to this idea. The Hawking radiation. You know the event horizon of a...
3. ### MHB Invariance of Asymmetry under Orthogonal Transformation

Show that the property of asymmetry is invariant under orthogonal similarity transformation
4. ### B Matter/Antimatter asymmetry

Is there anything in the current theoretical world that says that the universe has to have started with an equal amount of matter/antimatter, probably none at all and everything was created from photons. Could it be that there just happened to be a small amount of matter around or at least a...
5. ### I Antimatter-matter asymmetry, Law of charge

I'm new to Astrophysics and I'm just now learning about Antimatter-Matter asymmetry. I understand some of the theories involving how this imbalance couldve occurred, but I'm confused on why the net charge of the universe stayed at zero. It seems to me like if the antimatter particle changed to a...
6. ### A How to find the value of the baryon asymmetry in this paper

I'm trying to understand from this paper https://pdg.lbl.gov/2020/reviews/rpp2020-rev-bbang-nucleosynthesis.pdf What is the value of the baryon to photon ratio ##\eta=n_b/n_\gamma## as named in figure 24.1, but I can't get from the figure or the paper how ##\eta## is of order ##10^{-10}## Any...
7. ### I Exploring Matter-Antimatter Asymmetry in the Universe

Hello! I don't know much about this topic so I apologize if my question is not very clear. I understand that one of the conditions required to explain the matter-antimatter asymmetry in the universe is to have CP (charge-parity) violation. We have CP violation in the standard model (SM), in the...
8. ### I Asymmetry in Stokes' theorem & Gauss' theorem

Stokes theorem relates a closed line integral to surface integrals on any arbitrary surface bounded by the same curve. Gauss theorem relates a closed surface integral to the volume integral within a unique volume bounded by the same surface. What causes this asymmetry in these 2 theorems, in the...
9. ### Single Propeller load asymmetry in turns?

Single Propeller load asymmetry in turns Does this have a formula, and what is the current Flight Physics consensus of the effect of this on turns? G.

16. ### B CPT asymmetry question, in regards to recent experiment@CERN

Hi, I'm a high-school student, so it would be nice if someone could answer this question without a huge amount of terminology. I heard that recently at CERN at the BASE experiment, the magnetic moment of an antiproton (to nine places is the exact same as the magnetic moment of a proton..) I was...
17. ### B Matter - antimatter asymmetry

What does quantum mechanics have to say about this aspect? Matter usually differs by antimatter having opposite charge. It is said that the Universe in the early stages should have created equal amounts of matter and antimatter. The total charge is conserved no matter the interactions and if...
18. D

### A Asymmetry parameter while relating proper time with distance

In special relativity, we know, (proper time)^{2} = - (proper distance)^{2}. But, in Causal Dynamical Triangulations (CDT), they introduce an asymmetry parameter \alpha as, (proper time)^{2} = - \alpha (proper distance)^{2} [Q. 1] Can you please explain me about, why we need to introduce \alpha...
19. ### A Can slow change solve the metalaw problem?

The standard argument for the claim that time "must" be an illusion is the metalaw problem, that asymmetry such as fundamentally irreversible time in which the future literally does not exist would allow the laws of physics to change and we have not detected any change of the laws of physics...
20. ### I QFT operators time/space asymmetry?

I'm slowly working through Srednicki's QFT book and I had a question about section 3 (canonical quantization of scalar fields). At one point, he shows that the creation and annihilation operators ##a(\mathbf{k})## and ##a(\mathbf{k}')## are time-independent via the equation: a(\mathbf{k})...
21. ### General Relativity asymmetry identity

Homework Statement I have ##R^{u}_{o b u } F^{o}_a - R^{u}_{oau}F^{o}_{b}## and I want to show that this equal to ##2R_{o[aF^{o}_b]}## where ## [ ] ## denotes antisymmetrization , and ##F_{uv} ## is a anitymstric tensor Homework Equations Since ##F_{uv} ##is antisymetric the...
22. ### I Matter antimatter asymmetry

I need someone to clarify where I have erred: At the start of the universe, there should have been equal amounts of matter and Antimatter created, but we appear to live in a matter dominated universe. If matter and antimatter mutually annihilate into energy, and energy and matter are...
23. ### I Something I noticed about Doppler asymmetry

Good day, I was playing a bit with a Doppler effect scenario and tried to combine it a bit with Special Relativity and I concluded something that I don’t quite understand, or that I at least don’t get the meaning of. I am aware that the scenario and my concluded formula don’t describe the full...
24. ### I Decoherence and time reversal asymmetry

Layman question(s), but I hope not too stoopid -- many thanks to anyone with the patience to read and attempt even part of an answer, or share a possibly relevant link! I've got time today to follow and read links... 1) Saw a recent 'popular' article discussing that darn Cat as if still a...
25. ### B Explanation of the asymmetry of the Universe

Hi My academic background is in philosophy, and I know very little physics. My attraction to the principle of sufficient reason motivates my question. My understanding of one theory of the origin of the universe is that it started with a "singularity" which then exploded into our universe. It...
26. ### I Asymmetry in Doppler effect

Hi All, What is the explanation for the fact that doppler effect has an asymmetry with relation to the relative movement fo the source and the observer? For instance, ## \frac{v + 5}{v} \neq \frac{v}{v -5}## The version I have seems to be somewhat truncated to me; it simply relates this fact...
27. ### I Axis of Evil": Power Asymmetry in the Universe

When cosmologists talk of the "axis of evil" are they referring to the hemispheric power asymmetry or is that considered a different anomaly?
28. ### Asymmetry in the Doppler Effect for sound

I'm a bit confused about this. So say there's an observer and a source of sound. If the observer moves towards the source of sound, the frequency seems to increase because he encounters more wavelengths in the same amount of time. In a second case, if the source moved towards the observer, the...
29. ### Time Asymmetry in Quantum Mechanics

Hi all, I am reading the book "Emperor's New Mind" and have a question related to time asymmetry in state vector reduction (p.458) in quantum mechanics. Consider the following situation, as presented in the book: Suppose I have closed room with a lamp L, which emits light in some fixed...
30. ### Need clarification about asymmetry term in Bethe and Weizsäcker formula

well ... we are studying bethe and weiszacker semi empiric formula , and i am confused . specifically about the third term the asymmetry term and how it lowers the binding energy . so just so i know that i am getting this straight , originally the binding energy no matter the nucleus is...
31. ### Seesaw mech, CP violation, leptogenesis, lept/bary asymmetry

I'm trying to get my story straight on explaining the universe's matter-antimatter imbalance. So far I understand CP violation in neutrino oscillations (PMNS \delta parameter). And I think I'm right in saying that then a 'leptogenesis' process generates an excess of leptons over antileptons...
32. ### Asymmetry between probability distributions

I have made an interesting observation that I can't explain to myself. Think about a prior probability P and a posterior probability Q. They are defined on an event space W with only three elements: w1, w2, and w3 (the number of elements won't matter as long as it's finite). The Kullback-Leibler...
33. ### Asymmetry in MDS: Question on Unilateral Love & Hate

I am perplexed by an example given in an article about asymmetry in MDS (multi-dimensional scaling). You don't need to know anything about this to answer my question. It's all very intuitive. There are six people. They have various likes and dislikes for each other, which are asymmetric (as one...
34. ### Hubble redshift and calculation of galactic rotation curves

I am interested in whether it is necessary to account for the effects of the Hubble Redshift in determining the rotation velocities of galaxies exhibiting keplerian motion and, in particular, whether the associated spatial expansion of the Universe is known to result in spectral shifts that...
35. ### Twin paradox and asymmetry

Dear PF Forum, Can someone make it clear for me? Perhaps I should ask a very simple question. Concerning just one direction. The distance between Earth and Star T is 100 lys. The clock is synchronized for A and B And as PeterDonis pointed out at my previous thread. Which I believe 87% is an...
36. ### Does Chiral EM Asymmetry Imply Matter-Antimatter Asymmetry?

A Science Daily report discusses observations of cosmic gamma rays that suggest that magnetic fields in the universe disproportionately have left handed rather than right handed helicity. It goes on to suggest that under a 2001 theory of another physicist that this could explain...
37. ### Baryon Asymmetry explained by MWI

I did some cursory searching, and I couldn't find this idea being discussed, so I thought it would be a good idea to bring it up here. Is there any reason why a valid explanation for baryon asymmetry isn't that we happen to live in a world branch where there was a significant asymmetry in the...
38. ### Exploring Asymmetry Momentum Transfer for Space Propulsion

Momentum Drive =============== Just playing with some ideas on rocket propulsion in space based on asymmetry momentum transfer. Any reason why this is not workable? :-p 1. Let m1 = 100 kg robot arm at one end of a cylinder; m2 = 100 kg robot arm at opposite one end of the cylinder; m3 = 10...
39. ### Possible Explanation for Baryon Asymmetry

The reason why there is far more matter than anti-matter in our universe is because we are going forward in time. But if we reverse the direction of time anti-matter will become more prominent and I believe that at singularity there is a balance between both of them. The interaction between them...
40. ### A Thought on the Apparent Asymmetry of Time (the "Arrow of Time")

I had an interesting thought regarding the "arrow of time" and, with the hope of getting the opinion of someone possessing more relevant knowledge than do I, I'm posting it here. Essentially, I thought that it may be productive to contemplate the notion of a unidirectional flow of time. I do...
41. ### Gravity and time and space translation asymmetry

Suppose we have a test mass located at some point above the earth. It is allowed to free fall down toward the earth. It passes through a closed surface. Prior to entering the surface it has an initial momentum pi and initial kinetic energy kei. After leaving the closed surface it has...
42. ### Sound Doppler shift asymmetry confusion

I have come to learn that the Doppler shift equation is asymmetric. That is, the Doppler shift is not the same when source is moving towards the observer or when the observer is moving towards the observer (both with same speed). I have looked at the derivation of the Doppler shift equation...
43. ### Unconsidered source of CP asymmetry?

I constantly see references to the "strong CP problem" which is basically just the fact that the CP asymmetries in the SM are not large enough to account for the observed CP asymmetry in the universe. What I find odd is that nobody ever mentions the HUGE CP asymmetry caused by our current...
44. ### True Or False: Symmetry, anti-symmetric, asymmetry.

Homework Statement State whether the following are true or false. If false, give a counter-example: 1. ≽ is not symmetric \Rightarrow ≽ is not asymmetric 2. ≽ is not symmetric \Rightarrow ≽ is not antisymmetric 3. ≽ is not antisymmetric \Rightarrow ≽ is not asymmetric Homework...
45. ### Isospin Asymmetry in Nuclear Matter

Hi all what is meant isospin asymmetry for nuclear matter ? thanks alot
46. ### Is the asymmetry mentioned in 1905 SR paper fully removed?

In his 1905 paper introducing special relativity, Einstein calls attention to the asymmetry in the classical treatment of the relative motion of a magnet and a conductor: In a previous post, it was explained to me that, when the conductor is moving, the electromotive force has "in itself ...
47. ### Mitigating Loss/Gain Asymmetry ?

In doing some calculations the other day I came across the concept of "Loss/Gain Asymmetry". After spending sometime searching I was only able to find cursory information on the subject was hopeing someone mind be able to answer a question I had on the subject. In a scenerio where a 100 units...
48. ### AFB & Asymmetry Charge: Understand the Link

My question is: What is the relation between the AFB and the asymmetry charge?
49. ### Dark matter/Dark antimatter Asymmetry?

is there evidence to believe that there is an Asymmetry?, for example from the very early universe when there was interaction and annihilation between dark matter and matter
50. ### Can Non-Conservation of Momentum Be Explained by an Asymmetry of Space?

In the same way that momentum is conserved if and only if space is symmetric it can also be said that whenever space turns asymmetric momentum (of each individual particle) will not be conserved generating a force. Thus can we equate force with an asymmetry of space?